Tutorial 2: Birth of the Placenta

Birth of the Problem Placenta During Childbirth

4. Procedures for Management of Third Stage Hemorrhage due to Uterine Atony

Definition:

The classic definition of an immediate Postpartum Hemorrhage is the loss of 500 cc or more of blood. It is useful to remember that, even in the normal course of an uncomplicated birth with no interference such as medications in labor or assisted birth procedures, the amount of bleeding may be variable. The amount of usual blood loss in the third stage of labor has been documented as little as 50 cc of blood and as much as just under the 500 cc designated as a postpartum hemorrhage.

The Incidence and Prevalence of Postpartum Hemorrhage and its Effects

Mortality:

The World Health Organization estimates that worldwide, 585,000 die each year in pregnancy and childbirth. The major reasons listed are hemorrhage, obstructed labor and infection. The incidence of deaths due to hemorrhage is estimated at 24.75% of all maternal deaths worldwide.

In the United States, a report of pregnancy-related mortality from 1991 - 1999 summarized data based on statistical information from multiple sources. Embolism (20%), hemorrhage (17%) and pregnancy-induced hypertension complications (16%) were the three leading causes of 4,200 pregnancy-related deaths for all women. However, only 68 (2.7%) of the 2,519 subset of deaths after a live birth were due to hemorrhage.

Of equal concern though, is the incidence of hemorrhage which may not only threaten death, but which also causes delays in maternal recovery, ability to care for an infant, and decreased function due to fatigue.

A study of the magnitude of maternal morbidity during labor and delivery in the United States from 1993 - 1997 presented the first population-based data to be published. Data was obtained from the National Hospital Discharge Survey (NHDS). Maternal morbidity during labor and delivery was defined as "a condition that adversely affects a woman's physical health during childbirth beyond what would be expected in a normal delivery "Maternal morbidity was divided into obstetric complications, preexisting medical conditions, and cesarean delivery."

An obstetric complication was defined as "a condition caused by the pregnancy itself or by its management." Postpartum hemorrhage after vaginal birth was estimated at 2% of all maternal morbidity, for an annual estimated number of 75,729 women affected.

"Healthy People 2010 contains several new guidelines for reducing maternal morbidity, including an aggregate measure involving reductions in rates of maternal complications during labor and delivery." Certain causes of hemorrhage were deemed preventable, and where not preventable, "the goal is appropriate management to keep them from becoming severe or life threatening."

Deanel, Isabella. et. al Magnitude of Maternal Morbidity During Labor and Delivery: United States, 1993 - 1997. American Journal of Public Health, April 2003, vol 93, No 4.

Incidence of Specific Causes:

Specific causes for post partum hemorrhage are not usually given in statistical reports based on international or national data because this level of detail is not available. Therefore, the above data regarding mortality from hemorrhage includes all circumstances in the childbirth period. The morbidity data relates to the prevalence of postpartum hemorrhage after a vaginal birth. Individual research studies may provide data where they have focused on specific causes of hemorrhage in their studies e.g. lacerations, retained placenta, atony.

The Problem

The amount of blood loss that an individual may sustain without physiological evidence of stress is also quite variable. A vulnerable woman may have adverse alterations in blood pressure, pulse and general response indicating stress with less than 500 cc of blood loss. Conversely, it is possible for a woman to lose much more than 500 cc of blood without an apparent adverse physiological response. I remember a notable circumstance in my early career as a certified nurse-midwife (CNM) which demonstrates this point.

Clinical Case: I had been invited by my Yale School of Nursing nurse-midwifery instructor, Sally Yeomans, to attend home births with her at Chicago Maternity Center in Chicago, Illinois during spring break in 1961. She was employed there, when not at Yale, to teach the obstetrical residents from Case Western Reserve University School of Medicine, as they attended poor women in their homes for their births. This day, I was the student accompanying her.

The expectant mother was a large African American woman of high multiparity. She labored normally and gave birth without incident. As soon as the placenta was out, however, she had a massive flow of blood from her vagina. We later estimated the total at well over 1,000 cc of blood loss. My instructor immediately took over and the problem was brought under control. I monitored her pulse and blood pressure, and was amazed to find that it varied not a bit from her vital signs during labor. A few minutes later she arose and, squatting over a bucket in the corner of the room (there being no bathroom in that slum apartment) voided a measured 1,000 cc of urine. Again her vital signs changed not at all.

As we discussed the case, it was pointed out that her failure to void prior to the birth, with subsequent pressure of the full bladder, probably inhibited the expected contraction of the uterus as the placenta emerged. Since she was large, and obviously well hydrated, she was able to sustain the blood loss in the short term without adverse response. Needless to say, our follow up care took this into consideration.

Causes

As indicated in other sections of this tutorial, blood loss during and immediately after the third stage of labor may be due to a number of reasons. These were identified as:

Events prior to the birth of the placenta due mainly to faulty implantation:

failure to separate

partial separation with resultant bleeding

separation with failure to deliver

Events immediately after the birth of the placenta:

retained fragments

lacerations of the vagina, cervix, introitus, and/or perineum

atony of the uterine muscle due to poor uterine contractility

The management of all of these circumstances, except uterine atony as a unique reason, has been discussed in the previous sections. This section will focus on the most common reason for excessive immediate bleeding during and after the third stage of labor e.g. Uterine Atony

Prevention of Uterine Atony

It has been clinically noted that an empty bladder prior to the birth will enable the uterus to contract most effectively when the placenta is being delivered. Therefore, it is highly desirable to enable the woman to empty her bladder during the active phase of first stage labor and shortly before she enters the second stage of labor. A woman in normal labor should be allowed to ambulate freely. Therefore, it is very easy for her to walk frequently to the toilet to void. Women who are confined to bed should be assisted to void in bed.

Identification of Potential for Uterine Atony

Women who have very mild uterine contractions in the active phase of first stage labor, will probably have the same type of contractions during second and third stage. These may be sufficient to enable birth, especially in a multiparous woman, but often are not sufficient to result in effective contraction at the time the placenta is born. The birth attendant who notes the nature of the uterine contractions in late first stage labor will not be surprised by a uterus that does not contract effectively in the third stage of labor, and will be alert to the possible necessity for rapid response in the event of heavy bleeding. Preparation should include the availability, within the birth room, of appropriate injectable medications, and if needed, materials for an intravenous start for further medication. It may be desirable in some instances, to place an intravenous lock in a woman during labor who has a history of previous postpartum hemorrhage(s).

Immediate Actions:

A typical scenario of postpartum hemorrhage due to uterine atony:

The placenta delivers spontaneously followed by a heavy gush of blood from the vagina. The first step is to immediately do a bimanual compression of the uterus. In most instances this will stop the bleeding immediately, and will save blood loss. It will also contain further blood loss while medications are prepared and administered.

The procedure for Bimanual Compression is as follows:

Insert your gloved dominant hand into the vagina and against the uterine cervix while simultaneously placing your other hand over the uterus and encompassing it through the abdominal wall. Pull your abdominal hand downward and press your vaginal hand upward against the cervix and lower uterine segment until you feel the uterus encompassed between your two hands. This process should take just a few seconds. You will usually immediately feel the uterus contract under your hands. Hold it in place firmly without doing further manipulation. If the placenta has not been adequately examined, request the assistance of another person to examine it, or turn it over under your gaze until you have assured yourself that it is indeed complete and intact. Next, request an assistant to prepare medication as described below.

As indicated earlier, the goal of management of third stage hemorrhage is to minimize blood loss and avoid subsequent shock to the mother. Medications designed to contract the uterus provide an effective response to uterine atony. The following sequence of use of medications will provide 1) the most rapid response and 2) the most appropriate use of the characteristics of each of the three medications that are designed to contract the uterus and stop excessive bleeding from the placental site.

Methergine provides sustained uterine contractions rather than the more intermittent contractions of pitocin, hence an immediate, strong response to the atony. In some instances it may be the only medication required, thus avoiding an intravenous start.

An IM injection can be more rapidly achieved than an intravenous start, thus avoiding delay in providing some medication plus the bimanual compression you are doing. Since you already have an initial heavy blood loss, there should not be any concern about hypertension occuring from the Methergine in an otherwise normal mother whose blood pressure was normal during late first stage or second stage labor.

Expected Action:

Within 2 to 5 minutes, intense contractions of the uterus are produced. The amplitude and frequency of uterine contractions and uterine tone in turn impede uterine blood flow. Contractions of the cervix are also increased. Uterine contractions persist for 3 hours or longer.

Second Response: Oxytocin(Pitocin) in IV Fluids:

As soon as your assistant has injected the IM Methergine, have him/her initiate an intravenous start with 10 to 20 International Units of Pitocin in 1000 cc (1 liter) bag of Lactated Ringers solution. The amount of Pitocin is a judgement call based on your assessment of the response of the uterus to the bimanual compression and Methergine. In most instances the IV should run initially at a moderate rate, and the flow reduced as the atony is brought under control.

Rationale:

The intermittent contractions of the Pitocin will complement the Methergine you gave IM and continue to sustain contraction of the uterus over the next several hours.

Neither the amount nor rate of infusion of Pitocin should exceed the degree to which the uterus is responsive. Too much or too fast will only cause extreme discomfort to the postpartum mother. Indeed, her discomfort with contractions is usually an indication that the rate of flow should be reduced, as obviously the uterus is contracting effectively.

An open intravenous line will enable rapid administration of other medications if the mother collapses.

Expected Response:

Oxytocin indirectly stimulates contraction of uterine smooth muscle and impedes uterine blood flow. Uterine response is immediate. Oxytocin (Pitocin) has a plasma half life of about 3-5 minutes. Therefore, the IV infusion needs to be continued to provide a steady flow of the drug. Uterine response subsides within one hour of cessation of IV administration.

Third Response: Hemabate

Hemabate should be reserved for use only in those instances where there is a clear indication that the above measures are ineffective. This should rarely occur. If it does, there is probably other pathophysiology occuring. At this point an obstetric consultant should be contacted in the event that high acuity medical or surgical procedures are needed.

This medication is an analogue of a naturally occuring prostaglandin F2alpha which stimulates the myometrial contractions of the gravid uterus, providing hemostasis at the site of placentation.

Hemabate should be used with caution because:

It is unnecessary in the vast majority of cases in which the previously described management has been conducted (tutorial author)

It is very expensive compared with Methergine and Pitocin (tutorial author)

The side effects are very uncomfortable and include nausea, vomiting, diarrhea, flushing or hot flashes and chills or shivering as the first five of about 70 other possible reactions. (package insert)

Expected Action:

Package Insert: "Hemabate is indicated for the treatment of postpartum hemorrhage due to uterine atony which has not responded to conventional methods of management. Prior treatment should include the use of intravenously administered oxytocin, manipulative techniques such as uterine massage, and unless contraindicated intramuscular ergot preparations.......In a high proportion of cases, Hemabate used in this manner has resulted in the cessation of life threatening bleeding and the avoidance of emergency surgical intervention."

IMPORTANT NOTE:

A woman who requires Hemabate, after other appropriate measures are unsuccessful, may also have problems which are beyond the scope of this tutorial, such as coagulation defects. Therefore, notifying your obstetric consultant when Hemabate is required is always an appropriate response.

Follow-Up of a Woman with Postpartum Hemorrhage

It is appropriate management to give the woman a 0.2 mg tablet of oral Methergine every four hours for six doses (24 hour follow up total) after the immediate management is completed and the mother is stable.

Because of blood volume changes, the hematocrit will not be accurate for 24 hours. However, one can assume that iron replacement will be necessary if the subsequent hematocrit is low. Postpartum follow-up should include counseling regarding foods rich in iron and Vitamin C (citrus), adequate fluid intake, and care in ambulating in case of dizziness. Many women will feel an increased fatigue, and should be encouraged to extend their resting recovery time during the next few weeks.